imagine the overhead of an extra location to box pairs of shoes. Where these employees steal these boxed pairs. good joke.
Also let’s multiple “competitors” consolidate packaging into one big operation. Or localized to destination. Also a space thing: can ship more in bulk and make it all fluffier closer to point of sale.
Shoeboxes, among other packages, are a lot of air, why fill your truck/container/aircraft “unit load device” with it.